1. Technical Field
The present invention relates to an ink, an ink set, a recording method, an ink cartridge and a recording medium. More specifically, the invention relates to an ink, an ink set, a recording method, an ink cartridge and a recording medium favorably used in an inkjet recording process.
2. Related Art
An inkjet recording system in which ink is ejected from an ink ejecting device which comprises a nozzle, a slit or a porous film has been widely used in printers due to its small size and popular price. In particular, a piezo inkjet system in which ink is ejected utilizing the mechanism of the deformation of a piezoelectric device, and a thermal inkjet system in which ink is ejected utilizing the mechanism of the boiling phenomenon of the ink caused by thermal energy, are characterized by their excellent resolution and high-speed printing property.
Generally, known inks include an aqueous ink containing water as the principal solvent component, and an oil-based ink containing an organic solvent as the principal solvent component. However, it is known that there are problems such as solidification of a colorant in the ink, which is caused by the water used for the solvent of the aqueous ink vaporizing over time, due to its high vapor pressure.
Especially in the case of ink for an inkjet recording system, the diameter of the nozzle for ejecting the ink is small, and changes in conditions of the ink tend to greatly affect the ejecting property of the ink. For this reason, if the printing head is filled with the ink and left for a long period of time, water evaporates from the tip of the nozzle, causing a problem of clogging in the nozzle. As a result, there are cases in which ink cannot be ejected, or the ink will be ejected in a swerved manner, leading to deterioration in image quality.
In particular, from the viewpoint of preventing the nozzle from clogging when the ink is subjected to long-term storage, in a case where the ink has a high pigment concentration, no satisfactory solution has been provided by such methods so far.